Modification of ZSM-5 zeolite for maximizing propylene in fluid catalytic cracking reaction

Phosphorus-modified ZSM-5 were prepared with hydrothermal dispersion. Compared with impregnation, the virtue of this method is reducing the loss of phosphorus in the process of post treatment. Cracking of light diesel showed that more pronounced cracking activity was obtained on the catalysts containing phosphorus-modified ZSM-5 prepared by hydrothermal dispersion than that by impregnation. The catalysts were tested in an advanced catalyst evaluation (ACE) unit. The prepared catalysts increased propylene yield by 3% at least than the reference catalyst. The reason can be attributed to the higher amount of phosphorus fixed on the zeolite prepared by hydrothermal dispersion and higher residual ratio of crystallinity.